Worldbuilding isn't easy, of course. Even Tolkien nods, for all sorts of reasons, and not least because (as he wrote in a letter to Naomi Mitchison) "even a committee of experts in different branches could not complete the overall picture": it's just really, really complicated. There are considerations of genre, too, which means that we demand different degrees and kinds of plausibility from different kinds of writings. This doesn't of course mean that writers should be able to play faster and looser with the possibilities because a book is for children (the reverse is true, if anything), but the plane of satire, for example, lies at an oblique angle to that of our own reality. To complain that some of the things More wrote about in Utopia don't add up may be to miss his point.
To be honest, though, I'm not too sure about the worldbuilding in this universe, either. For example, like most apes, I find that without training my brain doesn't work well with very large numbers. What about yours? How far away is Saturn? Is it about a) 14,000,000,000 km b) 1,400,000,000 km or c) 140,000,000 km? Without looking that up, I would just have to take a wild guess.
One of the last conversations I had with Diana Wynne Jones before she became ill for the final time turned into a series of mutual confessions of our ignorance about this kind of thing. It began with tarmac, I think. Considering all the thousands - millions? - of miles of tarmac road on this planet, and the fact that new tarmac has to be laid every few years, how come we haven't run out? For all the worry about oil and gas reserves, no one ever mentions that tarmac too is a non-renewable resource. And where does it all come from, anyway? It's not that I couldn't find out if I really tried, but there'd be plenty more questions of the same sort to take that one's place.
Then there was the question of war, and strategic objectives. We didn't get that either. If you're in a Mordor-like landscape where there are only one or two passes through otherwise-impenetrable mountain ranges, then sure - the one who controls the passes controls travel from one side of the mountains to the other. But in a country like England, with its gentle slopes and reasonably-sized rivers, what does it mean to say that City X or Hill Y or Ford Z is a strategically vital objective that allows you to control the country for miles around? Neither of us could really understand why an opposing army wouldn't just go round another way. (Actually, quite possibly she did understand this and was humouring me.)
I think for many of us, living in this world is a bit like using a car. For most purposes we're happy to accept that it works, without looking too hard at what goes on under the bonnet. Once you start to write, though, you not only have to be prepared to take an intensive course in engineering, you also have to understand the process of manufacture, how all the various components were sourced, how the metal was refined, where the ore was mined and how it was transported (along with the accompanying economics), to say nothing of the geology of its formation.
Only then, my friend, you will you be able to write about that trip to the shop to buy Pot Noodles, and thus win the Booker Prize.